1. Field of the Invention
Embodiments described herein relate generally to a fault detecting apparatus for detecting a fault based on a current.
2. Description of the Related Art
In general, connecting a plurality of cells parallel to obtain a large capacity of power has been known. In a large-scale photovoltaic system, for example, a number of strings connected to PV (photovoltaic) arrays are connected parallel. In addition, monitoring a current flowing through the strings to detect faults at the PV arrays has been known.
On the other hand, detecting a ground fault or short circuit by detecting a current in an electric circuit has been known (see, for example, Patent Literature 1).
To detect faults at all the PV arrays, however, current sensors need to be provided at positive and negative sides of all the strings. If the current sensors are thus provided, the number of current sensors is increased in the large-scale photovoltaic system. If the number of current sensors is increased, devices (for example, A/D (analog/digital) converter for signal processing) and wiring lines accompanying the current sensors are also increased. Such a fault detecting apparatus therefore causes increase in costs of the entire system.